High-powered chargers and battery packs have an over-temperature prevention system. With this over-temperature prevention system, the battery pack cannot be charged by the charger when the temperature of the battery cells is greater than a preset value. So the battery pack must be cooled. When the temperature of the battery pack is decreased to less than or equal to the present value, it can be charged. However, the cooling process generally requires a long time, and the battery pack cannot be charged quickly. Further, during the discharging process, the temperature of the battery pack may rise quickly, and the high temperature may reduce the useful life of the battery pack.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.